GMC 1995 Suburban Owner's Manual page 234

2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes until the
chocks absorb the load.
4. Re-apply the regular brakes. Then apply your parking brake, and then
5. If you have a four-wheel-drive vehicle, be sure the transfer case is in a
shift to PARK (P), or
REVERSE (R) for a manual transmission.
drive gear-not
in NEUTRAL (N).
6. Release the regular brakes.
When You Are Ready to Leave After Parking on a Hill
1. Apply your regular brakes and hold the pedal down while you:
Start your engine;
Shift into a gear; and
Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks,
4. Stop and have someone pick up and store the chocks.
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